Electronic components such as power transistors and power supply modules are sometimes provided with a heat sink for dissipating heat generated by the electronic component when placed in operation. The heat sink is typically made of metal and a portion of the heat sink is attached to, or placed in contact with, an external surface of the electronic component for dissipating the heat generated by the electronic component. When the heat generating component is a relatively large component such as a power supply module, the heat sink may be attached to the component in a relatively straightforward manner such as by mounting the heat sink upon a top surface of the component. However, conventional techniques used for attaching a heat sink to a large component may not necessarily be effective when applied to electronic components and assemblies that are small in size.
For example, an electronic assembly that is known in the industry as a multi-chip module (MCM) may include several integrated circuits mounted upon a substrate in a flip-chip arrangement. Various discrete components such as surface mount resistors and surface mount capacitors, may be also mounted upon the substrate in the MCM. The discrete components are generally smaller in size (particularly in height) in comparison to the IC. One conventional approach to providing a heat sink upon an MCM involves using a metal cover that surrounds all the components in the MCM. The efficiency of such a heat sink may be sub-optimal due to a number of factors such as trapping of hot air inside the metal cover, insufficient contact with one or more ICs due to height differences between the ICs, and/or the use of low thermal conductivity thermal interface materials (TIM) at interfaces where gaps could develop due to expansion or contraction of materials having mismatched coefficients of thermal expansion (CTE).
In some applications, the metal cover may be used as an electro-magnetic interference (EMI) shield. However, such an EMI shield that surrounds all the components in the MCM may prove ineffective in some cases where one or more components located inside the metal cover may be exposed to EMI generated by one or more other components located inside the metal cover. It is therefore desirable to provide more effective shielding of components, particularly when the components are small in size and neighbored by various other components of different sizes.